[Intel-gfx] [PATCH v2 5/9] drm/i915/psr: Handle PSR RFB storage error

[Dhinakaran Pandiyan]

On Wed, 2018-04-18 at 15:43 -0700, José Roberto de Souza wrote:
> Sink will interrupt source when it have any problem saving or reading
> the remote frame buffer.
> 
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
> 
> Changes from v1:
> - printing a debug message when sink assert a error
> 
>  drivers/gpu/drm/i915/intel_psr.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
> index 4cb27faab707..558b08a43f9e 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -1156,6 +1156,18 @@ void intel_psr_hpd_short_pulse_handle(struct intel_dp *intel_dp)
>  		intel_psr_exit(dev_priv);
>  	}
>  
> +	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PSR_ERROR_STATUS, &val) != 1) {
> +		DRM_DEBUG_KMS("PSR_ERROR_STATUS read failed\n");
> +		goto dpcd_error;
> +	}
> +
> +	if (val & DP_PSR_RFB_STORAGE_ERROR) {
> +		DRM_DEBUG_KMS("PSR RFB storage error, exiting PSR\n");
> +		intel_psr_exit(dev_priv);

What do we achieve with an exit? Resetting PSR? I don't think that's
enough if the sink has storage errors. I think we should just disable
PSR here too.

> +	}
> +	/* clear status register */
> +	drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_ERROR_STATUS, val);

So the other two errors are not handled, silently clearing them isn't
right. How about at least printing a debug with the read value and
saying the error wasn't handled?

> +
>  	/* TODO: handle other PSR/PSR2 errors */
>  dpcd_error:
>  	intel_psr_schedule_activate_work(dev_priv);